Acta Cryst. (2007). E63, i180-i181  [ doi:10.1107/S1600536807044765 ]

The whitlockite-related phosphate Ca₉Cr(PO₄)₇

I. V. Zatovsky, N. Y. Strutynska, V. N. Baumer, O. V. Shishkin and N. S. Slobodyanik

Online 21 September 2007

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean (P-O) = 0.003 Å
• R factor = 0.030
• wR factor = 0.073
• Data-to-parameter ratio = 15.8

checkCIF/PLATON results

No syntax errors found




Alert level B
PLAT430_ALERT_2_B Short Inter D...A Contact  O1     ..  O10     ..       2.63 Ang. 
PLAT430_ALERT_2_B Short Inter D...A Contact  O1     ..  O10     ..       2.63 Ang. 
PLAT430_ALERT_2_B Short Inter D...A Contact  O1     ..  O10     ..       2.63 Ang. 
PLAT430_ALERT_2_B Short Inter D...A Contact  O6     ..  O6      ..       2.68 Ang. 
PLAT430_ALERT_2_B Short Inter D...A Contact  O6     ..  O6      ..       2.68 Ang. 

Alert level C
STRVA01_ALERT_4_C           Flack test results are ambiguous.
           From the CIF: _refine_ls_abs_structure_Flack    0.590
           From the CIF: _refine_ls_abs_structure_Flack_su    0.040
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.33 Ratio
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.11      
PLAT430_ALERT_2_C Short Inter D...A Contact  O2     ..  O4      ..       2.89 Ang. 
PLAT430_ALERT_2_C Short Inter D...A Contact  O7     ..  O8      ..       2.88 Ang. 

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           29.99
           From the CIF: _reflns_number_total               2161
           Count of symmetry unique reflns         1121
           Completeness (_total/calc)            192.77%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1040
           Fraction of Friedel pairs measured     0.928
           Are heavy atom types Z>Si present        yes
PLAT033_ALERT_2_G Flack Parameter Value Deviates 2 * su from zero.       0.59      
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K    
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K    
PLAT794_ALERT_5_G Check Predicted Bond Valency for Cr1         (3)       2.71      
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1      

   0 ALERT level A = In general: serious problem
   5 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   6 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   9 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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